This invention relates to a user interface, a printing system using the user interface and print control method and, more particularly to a user interface employed for forming various types of color images by an ink-jet method, a printing system and a print control method using the user interface.
Printers and printing units in copiers and facsimile apparatuses print an image comprised of a dot pattern on a print medium such as paper sheets or plastic thin films, based on image information. These printers and printer units use printing methods including the ink-jet method, a wire-dot method, a thermal-transfer method, a laser-beam method and the like. An ink-jet printer that employs the ink-jet method performs printing by discharging ink droplets from discharge orifices of a printhead onto a print medium.
In recent years, various types of printers have been widely used, and there are needs for high-speed printing, high-resolution printing, high image quality, low noise and the like. The ink-jet printer can be regarded as a printer that meets these requirements. Since the ink-jet printer performs printing by discharging ink from a printhead, it can perform printing avoiding contact with a print medium. This obtains quiet and very stable print-output.
By virtue of recent development of various digital cameras, digital video cameras, CD-ROMs and the like, pictorial image data can be easily handled by an application program on a host computer. The printer as the output device of the system is required to have an ability to output such pictorial images. Conventionally, a high-quality silver-chloride type printer which inputs digital image data and performs printing based on the input data, or an expensive sublimating type printer dedicated to picture output by using sublimation type dyes, have been mainly used to output pictorial images.
However, the printers for exclusively printing picture images are very expensive. One of the reasons for high prices of these printers is that the silver chloride method is employed as the printing method, which requires a very complicated image formation process and increases the printer size so as to preclude desktop use. Further, in the sublimating type printer using sublimation type dyes, as the size of available print medium increases, manufacturing and running costs of the printer main body greatly increase. Accordingly, such printers have not been suitable for home use. In addition, these printers are designed on the premise of using a particular print medium. That is, these printers, for a limited purpose, are not suitable for various types of printing as performed in domestic or general business environments. For example, in the above printers, it is impossible to print word-processed documents or graphic images on various types of print media, especially normal paper sheets, as usual printing, -and as specific printing, perform pictorial printing of picture images on a particular print medium.
In advanced printers, especially in the ink-jet printer, image quality of printed pictures is greatly improved due to improvement of image processing, coloring material, print media and the like.
In case of ink-jet printers, it becomes very common that one printer can selectively perform monochrome printing or color printing by employing a well-known exchangeable ink cartridge where a printhead and an ink tank are integrated. This type of printer has been made so as to attain most users' desire, i.e., enhancement of monochrome printing function for high-speed output of word-processed document images and color printing function for output of color-graphics, by using limited resources of one printer. The enhanced functions include an optimizing function to identify the type of an ink cartridge and switch print control appropriate for an ink cartridge for monochrome printing (monochrome ink cartridge) to/from print control appropriate for an ink cartridge for color printing (color ink cartridge), based on the identified type of ink cartridge. Note that at the present time, the exchange of ink cartridge is performed only for replacing monochrome ink by color ink and vice versa.
Further, in color output, various studies have been made for many years to improve tonality representation of color graphics printing. For this purpose, methods for enhancement have been proposed with respect to the printers, and they have been adopted at a practical stage. For example, to improve drawing capability, the print resolution for drawing can be increased to a higher level than that of ordinary color print mode. Otherwise, to increase the print resolution of the printer, it may be arranged to send multivalued data as print data to the printer and perform multivalue output by using subpixels.
Further, to perform pictorial image output by an ink-jet printer, there has been proposed from several years ago a printing method for printing a color image on a print medium by simultaneously using coloring materials, each having different pigment concentration. For example, the ink-jet printer generally uses four coloring materials of C (cyan), M (magenta), Y (yellow) and K (black) colors or three coloring materials of C, M and K colors. On the other hand, a printer, which performs printing by simultaneously using two types of coloring materials of different pigment concentrations with respect to each of the four C, M, Y, K or C, M, K colors, has been proposed. In this printer, a color representation range can be greatly widened, and further, with respect to a high-brightness area (area where print dots discretely exist on a print medium) in an image, graininess of the area can be greatly mitigated by performing printing with coloring materials of low pigment concentrations. Contrary, with respect to an area having low brightness and high chromaticness, an image of high color development where graininess is mitigated can be obtained by performing printing with coloring materials of high pigment concentrations.
However, in the above printing, it is necessary to hold various kinds of coloring materials within one printer, which causes complexity of the printing system. Further, as most users frequently perform monochrome printing, it is wasteful to always hold coloring materials of low pigment concentrations which are used on rare occasions. Furthermore, in consideration of the entire size of the printer, the size of the printhead cannot be increased over a predetermined size. This requires to shorten the print width or reduce the capacity of the ink tank per one coloring material.
The pigment concentration of a coloring material is determined by a necessary maximum density in the system to be designed, such that a necessary optical reflection density can be obtained from a maximum ink amount per a unit area on a print medium in the system. Generally, if the determination of pigment concentration is made so as to obtain the maximum chromaticness of a primary color defined by YMC color space, can be obtained by a maximum ink amount, approximately the maximum chromaticness of a secondary color, defined by RGB color space as mixture of two of the primary colors, can be obtained by respective maximum ink amounts of two primary colors. In case of widening the color representation range, to obtain the maximum chromaticness of a primary color by a maximum ink amount, the pigment concentration of the coloring material must be increased. This results in pictorial images showing very conspicuous graininess, on pictorial images, which never meets a requirement concerning image density in graphics image formation for business use.
Otherwise, to meet the above requirement, appropriate image density in pictorial image formation and in graphics image formation for business use can be obtained by decreasing pigment concentrations. In this case, ink amount is controlled such that the maximum ink amount of a primary color is twice (200%) of a normal ink amount (100%), and the maximum ink amount of a secondary color is four times (400%) of the normal ink amount. However, in a general ink-jet printer, as the maximum amount of coloring material is determined in accordance with the type of print medium, the number of available types of print media is limited. This limits the wide use of the ink-jet printer, and increases ink consumption amount, thus increasing running cost.
Further, more excellent image representation is becoming possible by using a plurality of inks of the same color having various ink densities. Also, it is becoming possible to use various types of print media in correspondence with various types of output images. For example, documents prepared in offices are generally made by monochrome-printing characters and graphs on so-called normal paper sheets used in copiers and the like. In case of printing natural pictures such as a photograph, it is preferable to use so-called coated paper as a print sheet from the point of image quality.
In this manner, as various types of ink can be used, various types of print media can be used, and various types of images can be printed, it is desired to perform image printing by using an appropriate combination of ink and a print medium in correspondence with the print purpose. However, it is troublesome for users to select appropriate ink and appropriate print medium in each printing since such selection increases operation procedure.